On The Block: A Patek Philippe Ref. 1518 With Unusual "Calendrier Perpétuel" Signature For Sale At Christie's Geneva

If you've seen our Reference Points: Understanding The Entire Lineage Of Patek Philippe Perpetual Calendar Chronographs, you'll already know all about the ref. 1518, the very first perpetual calendar chronograph. But you probably don't know about this unusual variant. This extremely early 1518 has an additional "Calendrier Perpétuel" signature above the calendar windows at 12 o'clock and is the only known example like this. This possibly unique piece will be sold at Christie's Geneva as part of the May 12th sale and is worth a closer look.

Even if we set the unique signature aside, this is a superb example of a ref. 1518. Only 281 of these watches were made during the 1941 to 1952 production period, due to the complex manufacturing process and high cost. When this piece was made in 1942, it would have retailed for approximately $1,000. Combine this with the outstanding condition – the dial has a great patina and is totally untouched while the case is still sharp – and you have a really appealing watch.

But, then there's that unusual signature at 12 o'clock. The "Calendrier Perpétuel" is crisp and when examined in comparison to the other signatures, it's clear that this was not a standard production siganture (lettering is slightly uneven and imperfect). There are varying theories on why this lone 1518 (as far as we know) bears this extra bit of text, but co-head of the Christie's Watch Department John Reardon believes that it must have been for marketing purposes. Customers would not have seen a perpetual calendar chronograph before and Patek Philippe likely used this in the display case on the Rue du Rhone as a way of explaining what the 1518 was and why the price was so high for the time. Only one other watch is known to bear a signature like this, and it's an abbreviated "Calend. Perpétuel" on a ref. 1526 that was sold back in May 2007 (also at Christie's Geneva).

This 1518 was sold in April 1943, confirmed by the Extract from the Archives, and still has its original fitted presentation box, a special box reserved for Patek's more complicated watches at the time. The caseback bears a small engraving that reads "Ma de Belen 5-VIII-1944" right near the pushers. It's unclear whether the date August 5, 1944 has any historical significance, though it could have marked a particularly important moment in World War II for whoever Ma de Belen was.

The estimate on this unusual Patek Philippe ref. 1518 perpetual calendar chronograph is $570,000 - $915,000 and you can see the official listing for details. You can also see the full online catalog for Christie's May 12th sale in Geneva here.

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